The present invention relates to a camera having an electronic flash equipment which can be used as an auxiliary light source for auto-focusing (to be called as AF hereinafter), and having a function in which the AF auxiliary light covers a range area regardless of its shooting view angle.
Conventionally, for an AF operation, AF detection auxiliary light is used when the brightness of an object to be photographed is low or the contrast is low.
Examples of the technique for emitting AF detection auxiliary light while an AF operation of a camera, are as follows. First, a technique in which an LED or light bulb serving as exclusive light emitting means is provided for an electronic flash equipment or camera body so as to emit AF detection auxiliary light, is known. Second, a technique in which the electronic flash equipment is appropriated, and a very small amount of light emission is created by utilizing its light adjustment function, is known.
Further, these days, as the usage rate of the zoom lens increases, an electronic flash equipment capable of controlling the flash irradiation angle, has been put into practical use.
More specifically, for example, Jpn. Pat. Appln. KOKAI Publication No. 9-61896 discloses a technique regarding an electronic flash equipment of a camera, including the first light emitting means for irradiating light at the first light distribution angle and the second light emitting means for irradiating light at a light distribution angle narrower than the first light distribution angle, characterized in that either one of the first and second light emitting means is selected to perform preliminary light emission which is carried out before an exposure to a film, thereby optimizing the amount of light emission in the preliminary irradiation of light.
However, in the case where there are a plurality of ways in the light emission by the flash equipment, it suffices if the AF auxiliary light covers an AF detection area only.
Further, with the technique disclosed in the above Jpn. Pat. Appln. KOKAI Publication No. 9-61896, where auxiliary light is necessary, the reliability of subject distance data obtained without using auxiliary light is low, and therefore it is not appropriate to control the irradiation angle based on such data. Further, the focal point detection area is situated at a center of the image or in its vicinity, whereas the flashing light for imaging covers the image in its entirety. Therefore, in the case where auxiliary light is used, the light is irradiated also onto the area other than the focal point detection area, thus wasting energy.